The invention relates firstly to a candle base material, as used for producing a candle with a see-through, transparent candle body, where the candle body has white oil and a copolymer as some of its constituents.
These types of candle base materials and, respectively, of candles produced therefrom are already known in a variety of embodiments. Reference is made, for example, to WO 96/34077 and WO 97/08282. The base materials for candles and, respectively, the candles produced therefrom which are known from these documents have a clear, transparent candle body.
The invention concerns the technical problem of finding an improvement for a base material of this type for candles and, respectively, a candle produced therefrom.
This technical problem is first and foremost solved by the invention the subject-matter of claim 1, which provides that the candle base material comprises, besides a white oilxe2x80x94an oil also termed hydrocarbon oil in the literaturexe2x80x94also synthetic paraffins in the chain length range from C18 to C20. In this way, it is achieved firstly that the candle is relatively closely related to conventional paraffin candles. Surprisingly, however, it is also achieved that a changeover from transparent to opaque and vice versa appears, the changeover being reversible and depending on a particular temperature, the change temperature. As long as the temperature of the candle base material and, respectively, of the candle is lower than the change temperature, the candle base material or, respectively, the candle body produced therefrom is opaque. Once this temperature is exceeded, a transition state is followed by the appearance of a substantially completely clear, transparent candle base material or, respectively, a candle of this type. This can be advantageous in a variety of respects. The candle may also serve as a temperature indicator. Secondly, when the candle burns in a relatively cool environment, a changeover from opaque to transparent, moving in the direction of the region of burning, can be observed to become established. This is moreover associated with corresponding optical effects. The characteristics of the candle body correspond to those of a conventional paraffin candle. It is also in particular self-supporting, and this also applies when sufficient of the paraffins mentioned have been added. On the other hand, the candle may also be formed by placing the candle base material for example in a receptacle. A wick passes through the centre of the candle body in conventional manner.
The addition of the copolymers mentioned is also significant for the structure of the candle body by Specifically, use may be made here of a variety of polymers. Examples of these are diblock, triblock, radial-block and multiblock copolymers. It is particularly preferable to use a copolymer known as xe2x80x9cKraton Gxe2x80x9d. This is a thermoplastic rubber. If the candle body is not solid, it has a gel-like structure.
The composition of the candle base material may vary very widely within the general teaching of the present application.
It is significant that the composition comprises a proportion of white oil and of the synthetic paraffins mentioned in the range from about 60 to 95%. Depending on how large a proportion of this is made up by the synthetic paraffins, there is a shift in the change temperature. The higher the proportion of the synthetic paraffins, the higher the change temperature. If the proportions are approximately equally weighted, i.e. in each case about 50%, the change temperature is about 20xc2x0 C. If the proportion of the synthetic paraffins is about 90%, the changeover temperature is about 30xc2x0 C. If the proportion of the synthetic paraffins is about 10%, the change temperature is about 6xc2x0 C.
Besides the synthetic paraffins mentioned, other substances, individually or in combinations, may also have been added to the candle base material. These are in particular poly-alpha-olefins, low-melting point paraffin fractions and products which have been obtained from naturally occurring fats and oils and have been prepared by a chemical modification process, such as for example butyl stearate. The poly-alpha-olefins may also have been provided in place of the synthetic paraffins mentioned. The same applies to low-melting point paraffin fractions and to the products which have been obtained from the naturally occurring fats and oils mentioned and have been prepared by a chemical modification process. Examples of these are stearic acid butyl ester, lauric acid methyl ester (tradename Edenor MEC 12 98/100) and triglycerides of caprylic acid (Myritol 312). Besides these synthetic products, it is also possible to use naturally occurring fats and oils (e.g. coconut oil).
The invention also provides a process for preparing a candle base material for a candle with a transparent candle body. To arrive at novel effects here with regard to the candle body, the invention proposes that a temperature-dependent change between opacity and transparency of the candle body is established by adding synthetic paraffin in the C18 to C20 chain range and/or one or more of the abovementioned other substances. In particular, it is preferred that the candle body is composed of from about 60 to 95% of a mixture made from white oil and synthetic paraffin in the chain length range mentioned, and that a relatively high change temperature is established by increasing or reducing the proportion mentioned of the paraffin, starting from a change temperature of about 20xc2x0 C. with equal proportions of the synthetic paraffin and of the white oil in the mixture.